Among the various media used to convey advertising or public service messages, billboards remain popular. This is due in large part to the effectiveness of billboard advertising and accounts for the multitude of billboards which line most of the well traveled highways and secondary roads. Billboards can also be found on building rooftops and other locations where they can be seen by the consuming public.
Billboards come in different sizes. A common size used for highway and roadside placement contains a display face that is 14 feet high and 48 feet wide.
Most of the billboard advertising used today is generated on a large, flexible sheet of synthetic material, typically composed of reinforced nylon. The display message is usually painted or printed on the sheet material by a computer-assisted process. The sheet material display may be rolled onto a large roll. The roll is transported onsite to the billboard where a crane or other lifting device lifts the roll into position about the billboard. The sheet material display is then unrolled onto the front face of the billboard. The edge portions of the sheet material display extend around the front face of the billboard to the back face thereof. A rod is hemmed into the edge portions of the sheet material display with openings that expose sections of the rod.
The edges of the sheet material display are secured and tensioned typically by a number of ratchet strap devices. The ratchet strap device includes a strap with a hook attached at one end (the hook is designed to connect to the exposed rod) and a ratchet wheel mechanism for tightening the strap and thereby tensioning the sheet material display.
The ratchet strap device suffers from numerous drawbacks. The strap, which is typically made of a nylon material, is prone to wear. It is therefore customary to replace the ratchet strap device every year. As several ratchet strap devices are usually required to attach a sheet material display to a billboard, the replacement of such ratchet strap devices every year can be costly.
The ratchet strap device is also disadvantaged because it has limited ability to accommodate variations in billboard support structure. In instances where there is no billboard supporting structure upon which the strap at the opposite end from the ratchet mechanism can be secured, the strap is often secured to the structure by ropes, cables, or additional straps.
The ratchet strap device further has limited ability to adjust to the expansion and contraction properties of the sheet material display which may be caused by external conditions such as heat, wind, etc. Sheet material displays tensioned by ratchet strap devices tend to lose their fit appearance over time and require frequent onsite readjustment and tensioning.
The need therefore exists for a simple, easy to use, adjustable, and durable sheet material display retaining and tensioning apparatus.